Re: [PATCH v4 4/7] soc: mediatek: pwrap: update pwrap_init without slave programming

[Sean Wang]

On Fri, 2017-10-13 at 16:07 +0200, Matthias Brugger wrote:
> 
> On 10/13/2017 11:41 AM, Sean Wang wrote:
> > On Tue, 2017-10-10 at 20:00 +0200, Matthias Brugger wrote:
> >>
> >> On 09/21/2017 10:26 AM, sean.wang@xxxxxxxxxxxx wrote:
> >>> From: Sean Wang <sean.wang@xxxxxxxxxxxx>
> >>>
> >>> pwrap initialization is highly associated with the base SoC, so
> >>> update here for allowing pwrap_init without slave program which would be
> >>> used to those PMICs without extra encryption on bus such as MT6380.
> >>>
> >>> Signed-off-by: Chenglin Xu <chenglin.xu@xxxxxxxxxxxx>
> >>> Signed-off-by: Chen Zhong <chen.zhong@xxxxxxxxxxxx>
> >>> Signed-off-by: Sean Wang <sean.wang@xxxxxxxxxxxx>
> >>> ---
> >>>    drivers/soc/mediatek/mtk-pmic-wrap.c | 91 +++++++++++++++++++++---------------
> >>>    1 file changed, 54 insertions(+), 37 deletions(-)
> >>>
> >>> diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
> >>> index 27d7ccc..9c6d855 100644
> >>> --- a/drivers/soc/mediatek/mtk-pmic-wrap.c
> >>> +++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
> >>> @@ -531,6 +531,7 @@ struct pmic_wrapper_type {
> >>>    	u32 spi_w;
> >>>    	u32 wdt_src;
> >>>    	int has_bridge:1;
> >>> +	int slv_program:1;
> >>>    	int (*init_reg_clock)(struct pmic_wrapper *wrp);
> >>>    	int (*init_soc_specific)(struct pmic_wrapper *wrp);
> >>>    };
> >>> @@ -999,9 +1000,12 @@ static int pwrap_init(struct pmic_wrapper *wrp)
> >>>    	}
> >>>    
> >>>    	/* Reset SPI slave */
> >>> -	ret = pwrap_reset_spislave(wrp);
> >>> -	if (ret)
> >>> -		return ret;
> >>> +
> >>> +	if (wrp->master->slv_program) {
> >>> +		ret = pwrap_reset_spislave(wrp);
> >>> +		if (ret)
> >>> +			return ret;
> >>> +	}
> >>>    
> >>>    	pwrap_writel(wrp, 1, PWRAP_WRAP_EN);
> >>>    
> >>> @@ -1013,45 +1017,52 @@ static int pwrap_init(struct pmic_wrapper *wrp)
> >>>    	if (ret)
> >>>    		return ret;
> >>>    
> >>> -	/* Setup serial input delay */
> >>> -	ret = pwrap_init_sidly(wrp);
> >>> -	if (ret)
> >>> -		return ret;
> >>> +	if (wrp->master->slv_program) {
> >>
> >> This if branch is really long and complex enough to put it into function apart.
> >>
> >> Thanks,
> >> Matthias
> >>
> >> PD please take into account the comments I made on v3 of the series.
> >>
> > 
> > I'll try to breakdown the long logic into the short one and use a flag
> > indicating the slave capability decides whether the functions is
> > required being enabled for the slave instead of slv_program which is
> > less meaningful. In this way, pmic_init will be more extensible when
> > more different SoCs and target slaves with various flavors into the
> > driver. And also take into accounts those suggestions you made in v3 in
> > the next version.
> > 
> > 	Sean
> > 
> 
> I totally agree, but I wanted to underline that right now the if branch under
> "if (wrp->master->slv_program)" is around 30 lines, so I think it would be a 
> good candidate to put it into it's own function. For example: 
> pwrap_init_encryption()

understood. I'll try to turn the code block into a function.

> As from what I understand from the commit log, slv_program in the end enables 
> encryption of the communication, right?
> 

yes. slv_program in the end will enable the security feature over the
bus such as the encryption and the signature for the data integrity when
the pwrap slave can support it.


> Regards,
> Matthias